Thank you for the information,
The species i really like are motoros, bd, leo , henlei and marbled maybe some hybrids too , close to my area someone had BDxHenlei pups forsale and also other breeds are easy to get in my area. A had a good talk with my Gf and she allowed me to go 250x140x60cm(8.2'x4.5'x2') this will make 2100liter/550Gal and when the garage is finished i allowed to build a 320x200x100cm(10.5'x6.5'x3.2')6400liter/1680gal pure plywood for better isolation.
I think these are better dimenions then before. And i might keep the small tank for pup growout when the big tank is build in the garage.
Will i be able to keep a pair of the rays above in the 250x150x60/8.2'x4.5'x2'?
If this isnt enough to start out im going to wait to build the bigger tank in the garage.