You won't be miserable with an 1100. In my personal opinion and experience an 1100 will take you all the way until you have the need need for the high dollar custom fit guns. An added bonus that I haven't seen mentioned is recoil. I saw the Browning BT-99 mentioned earlier. They kick like a mule. You can run hundreds of rounds through an 1100 in one day and not be bothered in the least.
The recoil is atrocious in some guns. That's why you see recoil reducers in the stock and release triggers to compensate for flinch. Beware a flinch is a hard habit to break.