Dymax T5s r not HO T5s. u can try asking one of the DIYers here to teach u how to make a HO T5 set or buy a set off them. but i dunno how much it is gonna cost. try browsing thru the DIY forum for more info.
Overhead filtration........ i wun suggest that. best if u hv a sump, else a cannister will do, but some work needed to maintain it.
more specs and details pls.