The attitude you are taking is extremely irresponsible. What will you do with your fry? if you sell them as endler's you'll be adding to the miss-match of genes floating around and restricting the number of pure endler's. It's an extremely selfish thing to do. If you go ahead with it anyway, at least promise to sell them on as fancy guppies (guppies are already endler's hybrids for the most part).
There is no point breeding endler's with guppies when you can keep a small tank of pure endler's and even make some money off selling them sicne endler's are quite rare.
What you get from teh hybrids is something that looks like your average fancy guppy like those on the top row here:
http
/guppyindo.com/Gallery3.html Like I said, there's no point hybridising these two fish when you can already get them in abundance at your LFS.
Platy with swordtail is also pretty pointless. The fry look like large platies with some having short swords. These are the very easiest hybrid to produce IMO. If you don't want to try something challenging, do this cross. It's much less damaging as platies and swords are already quite messed up for the most part.
In fact, the platies you own are likely to be hybrids themselves. The same goes for fancy guppies - most have some endler in them.
In fact, a lot of 'common' fish are hybrids - that includes mollies and several pleco species, as well as platies, guppies, variatus platies and swordtails. Not to mention a large number of 'assorted' mbuna cichlids are hybrids.
If you want to try breeding a hybrid that's worth your time, try the guppy X molly. It's a little more difficult but it's much better to do this as it's safer for the environment as well since it's unlikely they'll reproduce into second generations and it would be close to impossible in the wild. Plus the product would be a lot more interesting.
edit@ BTW, you won;t be able to tell which fry are pure endler's and which are guppy X endler's hybrids in teh first generation. They look almost identical - this is precisely why they are a problem - and also the reason it's so entirely pointless to breed them.