Nice! I looked at the first pic and said "Were's the Oscar?"! That is awesome. I love to buy babies and grow them out. there's no fun in buying adult fish.
I bought a 2.5" Tiger O on Feb 3rd of this year. Now, he's about 6.5-7", standard length (not counting tail).
expect them to grow about an inch a month, up to about 10". Feed small, varied meals often (I feed mine about as much as he can eat in 2 minutes as often as I can. and keep the water clean. the loaches and pleco should be good for cleaning up after the Os messy eating habits. Keep up with the frequent water changes.
as far as Os and Loaches not being compatible. I don't see why not (but I've never kept loaches).