Lupin if you look at the history of this fish you will see why they were given that name in the first place. It's a bit of a joke to hear "czech rams" etc. But technically they are Blue Rams - they are found in the wilds of the Orinoco River basin and in the flat plains of Venezuela and Colombia where they reside in shallow, small pools - hence why they tolerate much higher temperatures, imagine how warm their shallow pools get in South America! Not really German then.
FishBliss, this is how it works:
You can keep up to 5 in a 30 gallon tank in a 2m/3f group, as long as you don't have a hyper territorial male (which I do) and as long as you keep a close eye on them. However I and several others feel that it is better to have AT LEAST a 40 gallon tank for a group of 5.
In a 30 gallon, if you wanted a larger group, I would recommend only ONE male and 4 females (one will eventually be removed). Obviously in getting a larger group you also increase your chances of finding the m/f ratio's you want and can then remove one that doesn't fit (hence why you get 4 instead of 3). In this stocking ratio you will see interesting group interactions and it's very interesting to watch the fish and learn their hierarchical order, it also means that aggression is better dispersed at times when breeding becomes an incentive (for them, not you lol).
Obviously you are saying the LFS only has two at this point in time and that if you get two males, what are you to do - well what I recommend is that you ask the LFS if they would order in a large group of Bolivian Rams for you because you will be after up to 4 fish.
Explain that you are looking to get a set m/f group and that in order to do this you will probably need to bring back at least one or two fish to exchange in order to find the ratios, explain that all you need to do is determine the sex and as soon as that has been done you can make the appropriate changes and would they be ok with this as it may take up to a month to determine the sex, depending on their age and prior condition. I've done this with several fish stores until I got the exact group I wanted.
I'd be amazed if they said no, but it is their right to.
The same goes for just getting two fish - again explain BEFORE you buy the fish that you need a male and female, that at this point in time it is too unclear as to the sex of the fish in their tanks and that if you end up with two males you need to be able to bring one back in exchange for another until you find a female.
To sex them just take photo's of the whole fish, side on and get as clear a shot as you can of where their vent is, post it up or PM me and I will sex them for you.
A pair would work very well in your tank, but you need to make sure there is plenty of cover in the form of driftwood and vegetation (even if it is fake) and not overly harsh lighting, if you have quite bright lighting then increase the density of their cover - these fish will show you much nice colouration if given the right conditions.
The main reason you want more cover, particularly with just a pair, is that you are more likely to experience breeding. Male Bolivian Rams can be relentless when wanting to spawn and if the female is not up to it or not yet ready she can get worn down. So in that tank you would need to keep a closer eye on them, on the whole though they'll get on swimmingly, you may only occasionally find that you need to move the male into a naughty box (floating fry refugiums work well as they obviously let tank water flow through, whilst keeping the male separated).
During this time you would get the female fed up and conditioned for spawning so that she has the strength and "resources" to both put up with the male and mate with him.
I keep my spawning pair in a 30 gallon tank with a few Lamp Eye Panchax as dithers and they get on great, I do have a very hyper-territorial male though (which is rare don't worry) so I have to be particularly attentive to the female in-between spawns, still, even in my circumstance I very rarely have to separate the two.
Talk to the LFS, see what you can work out, I'll help you all the way with the rest.
I hope that helps.
Blair.