Best (obtainable) Resistors for RF (MELF HF Replacements)

[scopeman]

I have two R&S FSH SA's (FSH3 and FSH6( I am working on that have Vishay MMA204 HF MELF 400mW resistors in the front end (68 Ohm and 100 Ohm 2%). The problem is no one seems to stock the 68 ohm part. So I am thinking about using standard surface mount resistors in place of these. I believe that 1206 parts will physically fit but I was wondering if anyone has experience with a particular brand that is best for RF use. Thick Film? Thin Film? I would think that the trim method used would affect the inductance and the form factor and placement would affect the capacitance. Attached is a picture of the front end and tracking generator attenuators in the analyzers.

Thanks for looking!

Sam