Re-Stocking; Need Help Deciding Between Species.

[kiwifeather]

So after pondering exactly what I wanted from my 90L I decided to re-do it, more or less completely livestock wise. I decided to keep my cardinal tetras, and stock with other fish that would suit them and the tank the way they like it. My pH is a bit high for these species at around 7.1 or 7.2 (hard to tell which exactly) but I have wood in the tank with tannins leaching out of it like mad, and I'm thinking of adding peat and/or leaf litter (oak?) to the bottom of the tank as well. I was going to change from pebbles to sand but with my stocking I dont think I really need to and its quite a big effort. I'm also considering getting some low growing cover type plants for the front area of tank, but are there any that do ok in low light, low tech setups? Temp wise thinking around 26-28 or so?
 
I decided for my centerpiece to go with a pair of dwarf cichlids. Either rams or apistos of some kind. Keeping the 9 cardinals, and maybe upping the numbers, as well as adding either hatchetfish or pencilfish for a top dweller, as the cardinals nor the rams will really use the space.
So I'm seeking opinions on what exactly to get. 
 
1x Pair of either: Blue Rams (can get locally) OR Bolivian Rams OR Red Cockatoo Apistos (the only apisto I can see currently available in pair online, maybe able to get Trifaciatus
9x Cardinal Tetras. Already in tank, doing well. Maybe up numbers?
?x Marble Hatchetfish (I'd prefer Silver Hatchetfish as I think they are more suitable but only marbles avalible) OR Rocket/3-lined/Beckford/Red Pencilfish. I am not sure what numbers I would be looking at with these. Can someone advise?
 
I can't think of any bottom dweller (although the dwarf's will pretty much be one anyway) that will suit the substrate, nor with the other fish do I think I have room. Although I would like something to help keep algae off the glass between WC's when I clean it, as well as plant leaves clean. Are there any snails or other fish maybe that fit the bill, and wont worry eggs if the dwarf cichlids decide to spawn? 
 
Tank as it is right now:
 

 

[Brahmza]

I would recommend the Blue Rams! As for an algae eater, a few Oto cats would get the job done, and they stick to eating only the algae, so you wouldn't have to worry about the eggs. Many people say blue rams are hard to keep, and that you need an acid PH around 6.0, but I successfully kept 3 pairs in a 55G which had a PH of 7.0. It's hard to find a true algae eating snail that wouldn't devour every bit of vegetation in the tank, as well as fish eggs.
 
Edit: If you're worried about the blue rams and your PH, I hear Bolivian Rams have just as much personality, if not more. They're not as colorful as the blues, but are much hardier.

 

[kiwifeather]

The blue rams are certainly going to be easier to acquire lol, so they are certainly a high possibility, but I do really like the look of some of the apistos ahhhh choices! 
Otto's are another fish not available locally, so would have to ship them. I do like ottos but I worry about 1. the tank being overstocked with the pair, the cardinals and hatchets/pencilfish as well, and 2. feeding them since they can be picky apparently.
Did the blue ram pairs you keep spawn in that pH? I don't mind if mine breed per say, but I like letting fish do their natural thing if they so wish. Also how was their colour? The ones and the LFS are very pale and I dont know if its the pH, the age of the fish or the quality of the fish. 
I'm hoping to lower the pH a bit natural with the wood in my tank as well as adding peat and/or leaves to the bottom.

 

[kiwifeather]

SO I went with a pair of Blue Rams! Managed to get myself a confirmed pair at LFS! Now for the next choice.. Pencilfish or Hatchetfish hmmmm.... Ottos or no ottossss

 

[Brahmza]

To keep oto's you would need a steady source of algae in the tank, and if you don't it would be hard to keep them well fed. You could always try some sinking algae pellets and such. The blue rams are usually pale-ish when coming from most LFS, but as soon as they start to get adjusted to your tank they will start to develop tons of blue speckles throughout their body. My males started getting orange/red coloration on their dorsal and tail fins. I've never kept pencilfish or hatchets before, but the pencilfish might add a bit more activity to the tank. Also, a single dwarf gourami would be a nice addition to the tank as well. My rams laid eggs numerous times, but I didn't have the appropriate set-up to allow the eggs to mature and hatch. (I had a shoal of cories and khuli loaches that I'm sure enjoyed the snack every few weeks hah). A few sources say blue ram eggs have a hard time developing in water with a higher PH (6.5+), but I'm unsure.