Your double dome is good for the basking light --- NO coils in there tho -- I am going to post some websites for you for 3 fixtures you decide on what you want to get all 3 are really good they are all going to have the same distance for the placement of the tank depending on the screen on your tank -- you will need to let me know on that so I can help you
24" fixture
Zoo Med ReptiSun T5 HO Hood
this will come w/ a 5.0 bulb please get this one for a tank of 40 + gallon 22"
Zoo Med ReptiSun 10.0 UVB T5 HO
24"
Arcadia ProT5 12% UVB Bulb With Hood
or this one 2 ft fixture
Buy the SunBlaster NanoTech T5 HO - Fluorescent Fixture with 6400K Lamp at Hydrobuilder.com. Shop the entire line of SunBlaster products along with thousands of hydroponics supplies on sale now.
hydrobuilder.com
you will need to replace the bulb in approx 1 yr I recommend a month prior to
please let me know when you get it