Hold off until you have enough bottles. Another week is only going to improve your beer and give you time to collect what you need.
1 gallon = 128 US fluid ounces
1 bottle = 12 US fluid ounces
(4.5 gallons) * (128 ounces per gallon) / ( 12 ounces per bottles)
Assuming you have exactly 4.5 gallons, that's 576 oz, which is 48 12oz bottles.
Edit: oops, should read the whole thread before I post.
For what it's worth, I've capped twisties with my wing capper with no problem. I don't do it regularly, but in a pinch it's worked for me.
I agree, with buying 2 6-packs and waiting a week or 2 to bottle. Unless you have another beer ready to go into secondary, or you only have one fermentation vessel and want to make another.
Time makes beer amazing.