For the IP-056, I went with a Easton EC90 seat post, EA90 Stem, XMIplay riser bars, XMIplay clamp. For the IP-036, I went with the XMIplay post (Peter said he has had no further problems), XMIplay flat bars, Thomson 90mm stem, and Thomson clamp (which is nice and wide).
As for weight, the Thompson parts are definitely heavier. Both the Eason and Thomson parts are very high quality and I would not expect any problems with those parts. The bars from XMIplay also seem light, strong, and good quality. I would not hesitate in recommending the bars from XMIplay. The stem, seat post, and clamp are things that you will pay more for if you buy brand name parts but they are not that expensive and there are lots of choices.