I'm not going to try to answer the yeast question, because I know diddly about Belgian Tripels.
As for the hops, it doesn't look too bad.
If you are using Tinseth, then 1.085 is not the right gravity to use. You need to use the average gravity. If you are boiling 6g down to 5, and your OG is 1.085, your pre-boil gravity will be (1.085 - 1.000) * 5 / 6 + 1.000 = 1.070. The average gravity would therefore be 1.0775.
I ran it through Promash using Tinseth and pellet hops, and got an IBU of 34.5
This will be very slightly higher than your figure because my Promash is set up to boil off more than 1g, but the difference will be very small.
If you really want to calculate the IBU's without software, you can see http://realbeer.com/hops/FAQ.html#units
but this is likely to give you a headache