Jesse T: yeah it is pretty tight in there. Right now, I'm planning on using my beloved Tekin G10 along with my XXtra receiver. But I have serious concerns as to whether the two of them will fit in the space given. But, I used to fit the G10 and a similar sized receiver into the chassis space on my MR4TCpro. It has about the same amount of space or a little less than the Mission, so the two of them should fit.
If not, I guess I could use my GMV12 speedo instead.