rams arent that hard to keep. just make sure your water isnt excesively hard but you can always use a mixture of RO water and tap to make the water softer. best thing is just keep the water stats steady and from fluctuating too much.
i chose rams. guppies reproduce too much too easily, and bn plecs are pooper machines so would be constantly cleaning the water unless you only had a few in a large tank. the rams IMO are much more prettier than the others and when the fry are old enough can be sold for a good price.