You need to pick out what morphs are popular along with what morphs you like. I personally am not a fan of albinos really so breeding those, even if they were popular, just doesn't make sense. This is a hobby after all.

I'm starting off just now too so I only have 4 snakes, but I've been doing a lot of thinking about if I want to buy one or two more snakes now and what my breeding plans will be. I think for starting off co-doms are the best, recessives are just a bit too long and who knows what recessives will be popular next year. I'd be aiming for multi gene animals though both for the excitement and the variety.

Since you like BEL I'd go for a lesser x mojave pairing. It gets you to the same place but when you breed it to anything else you'll get lessers and mojaves instead of just all of one. The only thing I don't like about breeding BEL is that it's harder to tell what other genes you have in there. You can blacklight them and see patterns but some morphs might be hard to see. I personally like the super fires, but I don't think they're really comparable to BEL, just because they do have pattern still and if you're going for BEL you usually want the all white.

Like for everyone else though I'd recommend buying just females right now, they take at least 2 years and sometimes up to 5 years to be breedable. Buy females this year and then a male or males next year. You could get a male this year just to be sure he'll be ready in case you have a faster grower female that gets up to breeding size her 2nd winter, but if you don't have anything ready then you'll have spent a years worth of rats on the male along with the fact that morphs depreciate with time. So if you buy the male now it could be 200 for the morph you want, then in a year they could drop down to 100, or for the same 200 you can get an additional gene (or even another male of a different morph). This all depends on your budget though. If you have over a thousand dollar budget you could get some really nice snakes, if you have a 200 dollar budget you're probably looking at normal females with a 1-3 gene male (still not a bad idea really).