I agree that the bulb should fit that fixture with no problem. I do advise against using cheap fixtures though. they are definitely a get what you pay for item and while I haven't tested that one specifically, some of the cheaper fixtures I have tested don't produce as much output (same bulbs) as some of the better fixtures like SunBlaster, ReptiSun, and SunBlaze. I'm not certain if the difference is in the ballast/circuitry in the fixture, or the reflector quality (or both).
I agree that the bulb should fit that fixture with no problem. I do advise against using cheap fixtures though. they are definitely a get what you pay for item and while I haven't tested that one specifically, some of the cheaper fixtures I have tested don't produce as much output (same bulbs) as some of the better fixtures like SunBlaster, ReptiSun, and SunBlaze. I'm not certain if the difference is in the ballast/circuitry in the fixture, or the reflector quality (or both).
So, should I go for that one or better not? I looked up the Sunblaster fixtures and there are so many options on amazon, can you link me to the right one? I guess I'd be fine going with a reptisun t5 10.0 since I can pick it up locally without the risk of damage but I'd really like the Arcadia one more since I know that they're always good quality. Also, on lightyourreptiles it says it can be used up to 12 inches away or at least 12 inches, I don't remember. Is it like those full of crap advertising things where they go like "it can be used up to x inches away!" but it really is just garbage at that distance or is it legitimate? Since my beardy is 8 inches away from the lights, should I go with the 12 or 14%?
12-14'' is about right for the T5 with an Arcadia 12% or ReptiSun 10.0. If you have areas with little to no UVB then offering areas that are closer is fine. They are able to handle pretty high UVB but I don't recommend offering it all day and everywhere. The LYR Arcadia combo is great. I've used mine for over 3 years now and I can't recommend it enough. I also have a ReptiSun 10.0 T5 with a ReptiSun hood and found that it's output is very comparable. The Arcadia 12% bulb you linked to is good and you can use that one. The 22'' bulb should fit in this Sunblaster https://www.amazon.com/Sunblaster-904296-NanoTech-Fixture-Reflector/dp/B00AKKUBDQ/ Just keep in mind with this fixture (and the one you linked to earlier) the reflector doesn't cover the bulb all the way so they are better suited to being hung from a ceiling or a stand rather than sitting flush on a mesh or open top.
You would only need a converter if you are using the Arcadia D3 MVB light, but not with the
tube bulb. Arcadia's are terrific bulbs, both the tube bulbs & the MVB's both. We have been
using them both now, for quite awhile.
Those are standalone reflectors and are probably high quality (I haven't tested them to be sure). They might be able to be fitted onto the cheaper pangeareptile fixture but I'm not sure. This would only help if the reflector is the source of the shortfall rather than the ballast which I'm not sure of. The SunBlaster fixture and ReptiSun hood already have high quality reflectors built into them. I would probably pick up one of those and be done with it. They will serve you well for years.