Ryan, the honest answer is I dont know 100% about the Instructor requirements. It used to be that you had a PPL and FI course done but you could not be paid to instruct, then it changed to having to have a CPL and an FI course. Although there has been some talk in going back to the original I dont believe it has been implimented yet although I could be wrong!!
cheap hours building, go Florida simple answer. if you get over there in Mar/Apr the weather is nice, not so many thunder storms and you will bash out your hours in no time. The main advantage is that most airports there do not have landing fees and also you can get into much larger airports. (eg. I landed at Miami international, Orlando International and Sanford during my hour building)
I recomend researching flight schools that instead of renting the plane per hour let you lease it per week or day as my friend did that and traveled to around 20 states in East US during his hour building including a trip past the statue of liberty at 1,000 ft!!
make sure there are no restrictions on distance you can go from base and use your time wisely, dont get sloppy or lazy!!
good luck