What size is the tank and what is the lighting like?
Ambulia - Pretty hardy, doesn't need bright light. Can get fairly big but can be kept trimmed back.
dwarf sag - Again pretty easy to grow, slightly high light demand but nothing major.
red tiger lotus - Would do better with higher light and ferts but is relative undemanding in my experience. The biggest issue I would say with this plant is that it can get REALLY big and doesn't take to well to being trimmed back. I would not keep this in a smaller tank.
cryptocoryne wendtii - Pretty hardy and easy going. Supposed to be a slow grower but under the right conditions it can get pretty big, pretty fast (have a look at the planted tank link in my sig to get an idea).
ludwigia - Does better with high light and CO2/Ferts, however it will grow without them, just likely wont have as much red colouring. Pretty fast grower and get get big but does fine with regularly trimming.
water sprite - Another good choice, easy to grow, undemanding and fast growing.
Generally good choices. As its a betta tank though I'm going to assume that it maybe isn't very big? If the tank is on the smaller size I would dump the tiger lotus and maybe one of the the larger "stem" plants. In my opinion/experience too many stem plants in a small tank doesn't look as good and one of them will always end up out competing the other which means a lot of maintenance to keep them balanced.
Sand substrate should be fine. If you get black sand make sure you rinse it REALLY well before you use it. I would highly recommend using some root tabs in the substrate for the plants. Again assuming that there isn't going to be a lot of bioload in a betta tank the extra ferts will help and root tabs are a pretty fuss free way of taking care of that. Don't forget the most root tabs are gone within around 6 months so you will need to add some more.
Edit: Regarding PH/temp, etc. If you are in parameters for a betta all of these plants will be just fine.
