Florescent or the screw in type, or mercury vapor. I plan on using a flood light for basking. My tank is 48"/18"/18". But I have a custom top that adds 8 more inches to the height. It's not for the beardie though. It's so I can wire my lights up and have adjustable vents, with out seeing all the clutter. Just not sure what is is ideal. Price is not a issue here. Just want to get it right. I can use chains to raise and lower the light but the usable level of UV needs to reach a min. of 11" I can't lower the light any lower but can go up to 17" from the basking spot. If this didn't make any since I understand. I'm not good with words but just give me what you got. Thanks in advance.