I just deployed a bunch of 831's for remote office users (all of the sites have less than 10 users). They are all on DSL and Cable Links
I deployed a bunch of 806's a while back, but they went end of life. No throughput issues in either case. I think that the 800 series are pretty much fixed model routers (No Cards)
scroll down a little bit for the table. I keep this page in my 'Favorites'
http://www.cisco.com/en/US/netsol/ns340/ns394/ns171/ns125/netbr09186a00801f0a72.html#wp1001891
also a neat feature
http://www.cisco.com/en/US/products/hw/routers/ps380/prod_bulletin09186a008015d020.html
"What processes specifically and what other tools can i use to check throughput."
The bigger drain may be on the CPU if anything. I play with alot of stuff from Foundstone when it comes to testing. But note that one of the tools may be flagged as the UDPFlood trojan by your Antivirus
http://www.foundstone.com/