Flash recommendation

[wmvaux]

I have to say I know very little about flash, but have a 21st on at the end of the month and I'm expected to take photos which I don't mind, but as it's going to be indoors in a restaurant, I figure I'll need a flash set up better than the flash on the camera.

I plan to get into portraits and photography with lighting more down the track as I develop as a photographer, but at this stage I'm doing mainly landscapes/seascapes/cityscapes..etc
Now the issue for me is that I don't really know much about flash and I pretty much need to buy something today, so I have it before the date.
I have a Nikon D7100 and I'm thinking I need something like a speedlite and just have the light shooting off the ceiling. I understand there are masters and slaves, but at this stage I just want one to get me by and that may be used as a slave down the track when I buy something better as a master. I'm thinking of something up to $150 and have seen various ones on eBay, but I don't really understand yet what I should be looking for in a flash. I have seen a Yongnuo YN-510EX which has TTL but only in slave mode. I don't know if TTL only in slave mode is a problem or not.

I would appreciate some direction and help as to what I should be looking for in a flash or recommendations.

[Mark L]

No export here, but since no one's answered and you're in a hurry.
wetpixels does a lot of research before committing to something. So check his link in post #1 here ......http://www.ausphotography.net.au/forum/showthread.php?124604-New-YongNuo-YN500EX-flash-with-HSS
Think it's in you're price range and could be useful later.

[wmvaux]

Thanks Mark L, I have ended up buying a Yongnuo YN-565EX i-TTL Flash Speedlite if anyone has one or knows about them and can give me any tips or info, that would be very much appreciated.