How’s your budget?
You could do a 150 hps if your ventilation is good enough but you’ll have to do some solid training and also likely start a 12/12 light schedule fairly early on to keep it from growing too tall. That being said, you may get better yields out 150w hps vs 1 or 1 105w CFLs.
A few CFLs will likely be the cheapest option but yields may not be the highest. They can still be very good and there’s plenty of threads where people grew nice yields from a few CFLs so it can be done.
With the height and heat possibly being an issue a good LED panel would be awesome but also the most expensive route.
I’m flowering in space about a foot taller than that but otherwise the dimensions aren’t too far off and having success with a 150w HPS and 4 26w CFLs. Temps aren’t an issue but my intake temp is also around 65 degrees and is being pulled through the box by a 135 CFM fan.