Ok well 1) have to remember HDD makers see 1,000,000 bytes to a Megabyte were as the PC see's 1,048,576 bytes to a megabyte so always expect to lose on average 10% from what you bought to what the PC will say you have.
Now 1) I would NOT delete the recovery partition unless you reinstall with like windows or something because if your Vista fails or crashes for what ever reason and you DON"T have any recovery DVD's your screwed pretty much. Got to find a Vista disk that will work with you PC which OEM Disk will NOT work with Retail disk (Ones you buy in the store) when putting in the Vista Key thats on your PC.
2) If you REALLY want to get rid of it and you Really want to get that 8GB back because of space just get a new hard drive and clone it to the new hard drive which copies everything over and you have a bigger hard drive to work with.
I have a 320 Gig with me and the bigger partition i can make is 298GB. So if you got it to 302 thats as big as you will get. If you want bigger get a new hard drive.