A 6 bulb Tek is the same as a 5 bulb TX5.I forgot the price went up on the Aquactinics.Consider both about equal.
If money an issue than look at the Nova Extreme Pro and Catalina,both have IR but don't use the better material for the reflectors,so I've read.Those two comes with bulbs too.That would save you a $100 or more.
I like bluish color
If I had the Tek 4 bulb
GE6500k
ATI Blue plus
ATI Aquablue special 12k
UV Super Actinic
Tek 6 bulb,I would add these to the above......
UV Aquasun 10k
ATI blue plus
TX5,
ATI blue plus
UV aquasun 10k
UV super actinic
Ge 6500k
ATI blue plus(softies,lps) or 14k(sps,clams)
Warning:these are my choices in what I think looks good.Slightly on the bluer side.Its very similar to my set up