sure they can be trained, just feed them tap on the glass and they will come running from all over.. there hard to teach them to line up and beg ...

looks like va L001 for sure, post a better picture to be sure

Looks like Lo1 to me, I have 4 that are about 8"

If you can get a hold of some Aquamax #300 pellets try them or see sonic on aquabid for some of his power pellets they should like them both..

try using 8" long by 11/4'-11/2" pvc PIPE AS SPAWNING CAVES. I heat them up in boiling water till they get soft so I can flatten the bottom of the pipes to keep them from rolling around. I use one of those hang in the tank breeder net for hatching out the eggs. use lots of BB shimp and golden pearls ...

I was told that it's the males that like the caves they'll spent 95 % of there time in a cave..

The only pl*co I can think of that can fit you description is probably an Ancistrus sp. (L144). It's intereting, don't grow too big, eats algae and not too expensive. Good luck in finding it though. Next up would probably be the albino ancicstrus sp. 3 as already mentioned above. Try Aquabid.com ...