bulgie 

I worked at a place that made Ti frames, and we used those art.298 bosses on the road frames. You just drill a hole through the downtube (both sides) and the 298 bits thread into themselves. We used Loctite on them, never had a problem. I thought of it as a little cheesy until I saw a couple Merlin Ti frames that broke right at the welded-on bosses, and heard of several others as well, maybe the #1 place Merlins were known to break. I'd rather have a "cheesy" bolt-on boss than an elegant weleded-on boss that makes the DT break!

Merlin was probably welding them on without an argon purge inside, so welded ones (done right) don't normally make the frame break.

Anyway all this talk of Ti is off-topic, you're talking about alu frame. So your choices are more whether to use this screw-on type (which we got from Cannondale BTW, not from England), or a glued and/or riveted-on type. I don't think anyone welds them on, in alu. (Someone will let me know if that's wrong.) Glued-and-riveted could be a good way, but you'd need to find the parts, and I don't know where to find those.

Mark B