Mix...
the i60 is a great phone and it will be perfect in the Boost system if it has no problems!
First you do need a 32K sim to use the handset at it's best, so we have to get you to a site that will help you out..
http://pcs4lessllc.com/BoostMobileMain.htm »

A great site that specializes in Nextel/Boost equipment and accessories. They have 32K starter kits available as far as I can tell from the web site..I have purchased three 64K's from them and have had no problems so far. You can query them and they will get back to you within a reasonable time frame during the work week. If you have to get a 64K sim you will lose functionality of the phone book on the handset but all other services will be fine; DC, and Cellular. The Sim's he has are preactivated but it is not a huge deal to request the Market transfer from Customer Service 24-48 hours and I have seen them done within hours! $39 and a few days ...we will have you up and active ! We have also lowered our Cellular prices to a much more reasonable .20@minute 7am-9pm and .10@minute 9pm-7am and weekends.
Let me know if I can help...Thanks, Jess