4' F54 T5 HO bought one today got some questions

1. I know clf's are only good for 20" above the plants, So is a T5 then same 20" above or can you go higher, is it less then 20" I basically bought it for seedling and maybe clones later on.
2. I bought it at home depot, they only had cool white 4100k tubes, that is good for seedlings and clones correct, I looked on line for tubes that were 4' F54 T5 HO tubes in veg daylight 6500k and flower soft white 3000k I found them but you have to buy them buy the case 24 $129, or 48 $239 I don't need a case I only need two, so I was wondering if people here know where to buy them singly or in 2 packs I would really appreciate thank you

I know urban sunshine has them in 4 packs online for like 45ish dollars. That seems steep to me, did you check 1000bulbs?

Edit: spectralux 6500k 4' x4 33.56 ups ground approx 15 dollars.