I am now leaning toward the 10/22 upgrade, since I already have one. Changing the barrel is straight forward. So is changing the trigger group. I'm looking at the BSA scopes now - their 3x9x40 Mil Dot is $100. So for the extra $50 I might as well go for the 6x24 and get more magnification out of it.
Right now, I have a Simmons 3-9 x 40 on it and I got it zeroed at 100 yd. yesterday. It was originally at 50. The Simmons is fine at 50 and 100. Last time I tried it at 300, things got really dicey. With a 100-yd. zero, I'd have to raise the reticle 126 clicks to set it for 300. In mils, it's 9.63 - almost 10 Mil Dots. In MOA, it's 32.51. Here is where the 20-MOA base would be a great investment. For $40, I can now subtract 20 MOA from 32.51 that, leaving me with 12.51 MOA to have to adjust. That number puts me will within the range of five Mil Dots, so I could zero for 100 and hold Mil Dots to 300. I think the Simmons is too basic a scope to push those distances. It has a simple cross hair reticle and it doesn't take all the adjustments you click in sometimes. I think the Simmons is good for around where I have it. 300 is really pushing it, though I might give it another whack next time I go out there.
Speaking of BSA, they also make a series called "Sweet" which for .22LR has compensation drums for different bullet weights and out 300 yd. It's a simple cross hair, but you move the drum where you want it supposedly and you're dead on. The 6 - 18 model is $210, but you don't need a 20-MOA base. The 3-9 model is $150. But...if you want to practice working with Mil Dots, the Sweets are not Mil Dot and you won't get the practice of calculating and holding Mil Dots.