I'd use rear lift blocks to get the 2". You can get them tapered like mine so you shouldn't need shims from Trailmaster. Be sure NOT to get aluminum blocks. They break. Learned that the hard way. Don't forget longer u-bolts.
I went the other way around. I got the front poly spacers and rear 2" lift blocks, now I'm adding the 4.5" lift to it. Your could do an AAL but it will make the rear stiffer. I would recommend new LCA's and UCA's when you do this. They need to be longer. Check this chart out.
Lift......................LCA............./............UCA
********Decimal**Fraction**Decimal**Fraction
Stock........15.75.......15 ¾........15.00.......15
2”.............15.92.......16............14.88.......15
3”.............16.09.......16............14.92.......15
4”.............16.33.......16 3/8......15.03.......15
4.5”..........16.47.......16 ½........15.11.......15
5”.............16.62.......16 5/8......15.21.......15 ¼
6”.............16.97.......17............15.44.......15 ½
7”.............17.36.......17 3/8......15.74.......15 ¾
8”.............17.81.......17 ¾........16.09.......16
9”.............18.30.......18 ¼........16.50.......16 ½
10”...........18.82.......18 ¾........16.96.......17
Also, if you haven't already done this, you should get an adjustable track bar. I've got Rusty's HD adjustable track bar and bracket. 6" seems to be the magic number for these things if you still want decent flex.