There are sooooo many different picks to choose from and every thickness and size will make a different sound. For me, I play bass and I prefer sharp guitar picks: for some reason these are the most comfortable for me and I like the sound.
A bass pick will generally be louder (well, you'll notice when playing acoustically) and have more attack on your strings and a higher gain from your guitar signal, but if its more comfortable then there are actually thin-medium sized bass picks (like just the fender ones) that will give you a very similar tone to guitar.
I think in general, the tone will change based on the thickness of the pick and sharpness of the edge. I haven't seen sharp bass picks, they tend to be the normal rounded edges. So if you pick a similar thickness, just in bass pick size, I can't imagine you're messing with tone too much.
Picks are an easy thing to experiment with to find your best comfort zone while playing and your best tone (though it is not by far the defining tone factor) that are really cheap. If you think a big pick would be more comfortable for your playing, go for it! Try em out.