Noooo. I pushed my luck after reading MANY MANY MANY threads, articles, and charts about tire sizes and calculations.
The funny thing is that I found the lift didn't have too much to do with my clearance, since my lift was late in the mail and I put the new wheels/tires on anyways. Clearance was almost identical, and lock-to-lock was REALLY almost identical.
I decided to go with 275/55/20's which are 32" overall diameter and one of the larger sizes you can run.
Honestly the 275s are a weird size and most would rather run a smaller width. I was just going for the tallest sidewall possible while staying within 32" overall diameter. I had 22's on my Range Rover Sport - 285/35/22s, which sound big and looked big but were actually .1" smaller than the factory 19's at 29.9"!
A 305 has numerous BIG disadvantages. First of all, it's a 33.2" wheel which I believe is far too large (1.2" larger dia. than mine, and mine rub during a full-lock turn w/ 2.5" lift!) fitment-wise, and that's just height - width-wise it may simply be impossible. Second, you're turning 10% less revs/mile. I lost TWO MPG going to a 32" tire, and at 10% you're doing almost 67mph when your speedo says 60. Gearing and transmission programming is just not ideal for that, and she will drive like an absolute pig. Another thing is contact patch, which is similar to the other two I already mentioned, but I believe in both friction (dry pavement, regular MPG) and off-road in snow and such, most people don't want you floating on surfaces and say that smaller contact patch is better for snow and such.
Besides, I'm running 275s on a 9.5" wheel which is basically the largest width suggested. 11" rims are supposed to be the minimum rim width, and the "normal" rim width is 12"! It literally isn't even possible with the 9" rim you mentioned.
Anything in that realm would require custom offset or a specialty rim, so unless you're trying to pay 6k for a set of HRE's or something I wouldn't expect to even find a rim compatible with the sizes you're looking for. The 9" rim you're looking at is most likely designed for a ~255 stock tire, stock offset.
You wouldn't need to reprogram your various computers - but mostly because you can't anways lol. There would be no way to specifically reprogram your TCM and/or speed sensors. Gear ratios wouldn't be ideal, speedo would be off, shift programming will be off, and some ABS programming/behaviors will be off.
I would just stick within the realms of normal, or at least within calculated limits for these vehicles.