Also, don't worry too much about spotters who don't look real strong. Unless something goes catastrophically wrong (say you pass out in the middle of your lift without warning) a spotter will only have to "assist". You will still be able to lift much (most) of the weight, just not all of it.
Mind you, if the spotter looks like a harsh word will break him/her in half then maybe ask someone else.
You can also try to strip off weight if you don't have a spotter. Start with the heaviest weight you can comfortably and safely handle, then after one or two sets take some weight off & repeat the exercise. Not quite as good as a spotter but it's safer than struggling with the last set and risking getting pinned under the weight you're trying to bench.