Any chance you can put the smoker out back? If so, your choices will be unlimited.
Backwoods can be used inside, so long as you get the butterfly valve and run the chimney to the outside using some ducts.
Lastly, some folks build their own pits.
Rest assured, the commercial smokers are pretty pricey...several to $10's of thousands of dollars.
There's a used SOUTHERN PRIDE BMJ-1000 on Ebay for about $10,000 and a trailer mounted one for about $7K
Life's a party with a Backwoods Party!