Hi there
could you please describe in more details what do you mean by "doing the same on the WAN side"? Do you mean enabling HSRP between ISP R1 and ISP R2 devices? And were should be NAT implemented on your devices - on R1-R2 only from LAN (192.168.1.0) to WAN (10.10.1.x) or on ISP R1/R2 also?
From the first look, the main issue you may face with is how to avoid assimetrical routing - e.g. ensure that return traffic from WAN to LAN will be directed to currently Active HSRP device.
Please find below link to some useful information regarding SNAT - it can really help in this case; but please be aware that this feature is announced as End-of-Sale (http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6586/ps6640/end_of_life_notice_c51-611706.html )
http://www.cisco.com/en/US/docs/ios/12_2t/12_2t13/feature/guide/ftsnat.html#wp1035671
BR,
Nataliya