I've been commuting from NE and SE to Beaverton for a few years now. RT is 30 miles, so Hillsboro will be a bit further, depending of course on where your house and office are.
The Bike There map is a great resource. The hill may seem a bit daunting at first, but the advice about using the MAX is very appropriate. I spent my first winter taking the Max underneath it, from Goose Hollow to Sunset Transit center, then continuing the ride. It is a great help to working into a longer commute.
My route over the West Hills takes me up Terwilliger to Beaverton/Hillsdale Hwy, a beautiful and very safe route. If you want to go around to the North instead of the South, I'd vote against climbing Burnside, there is no shoulder and cars fly up it, plus there is construction going on for the forseeable future. Alternate routes include going through Washington Park (the bike path is a continuation of NW 24th ave, the street ends at Burnside, but the path climbs the hill) or going around (I'm blanking on street names here, but it should be on the map, take Lovejoy through the city, then turn right at the T and climb like hell until you reach Skyline.)
Portland is a fabulous biking city, the route you are describing will most likely be a 35-45 mile RT commute. Portland is one of the great places to live, but the suburbs are pretty much the same wherever you are, so by all means give the city a try.
Let me know if you want someone to play commuting route tour guide. I'm getting laid off next friday and should have some free time this summer.