The 5.5 inch rear tire is too wide for the Thruxton's swingarm, without offsetting the wheel to clear the chain.
I think sweatmachine has a great alternative by using wheels from an SV650: 120 front and 160 rear. I just searched ebay, there's plenty for sale and looks like front and rear could cost as little as $250. There's some machining involved to get them to fit, but the total bill should be less than $1400. Sweat is using the whole front end from an SV650, to improve the front suspension as well as use the SV's twin discs up front. Here's the thread ->
http://www.triumphrat.net/bonnie-own...ighlight=SV650
