Have you considered the RAF? From a military point of view there some options out there that would give you a good breadth of engineering experience.
If you want to get into the technical side of things there are opportunities in all major areas, airframes, propulsion, avionics, weapons etc, although it could be argued that these are reducing in number. I would only be speculating about rank/pay structure so I'll leave that for others to comment on. If your eyesight failed on colour blindness, then I would advise against going along the armament route.
<"No, cut the blue wire" we all chime>
If you want the engineering management side of things, then the officer route may be more suitable.
ericferret's comment about having a degree becomes very relevant here as a degree-level engineering qualification is required. Beyond the rank of Flt Lt, exposure to the aviation experience you desire would diminish greatly, so a Short Service Commission (SSC) of 6 years might be more suitable than a longer engagement.
Salaries as an Officer Cadet under training start at £13,881 and jumps to £26,371 (in the rank of Flying Officer) upon completion of 6 months initial training. Top level Flight Lieutenant pay max's out at £40,190, although many people get promoted to Squadron Leader before they reach the top rate. Squadron Leader pay starts around £42,570 and rises to £50,983, although it takes most people 15-20 years to get to top level. Note that there are few, if any, pay incentives for further qualifications as an engineer. There are also a limited number of sponsored MSc's available once you are in the service, but these require a 3-year return-of-service.
Hopefully I'm not over-simplifying this too much, but in a 6 year commission as an officer you can expect one tour 'on the line' as a Junior Engineering Officer (JEngO) where you will be the loathe of all the aircrew and possibly some/all of the 100 or so engineers that will work for you. Great fun if you have the cojones, not so good if you don't. Another tour might be running a shift on a depth maintenance facility. Another tour might see you 'in the rear with the gear' project managing enhancements to aircraft systems. Other, probably more boring, tours are available. Like I said, beyond that, you are likely to be tied up in policy, procurement and plans.
While you may not pick up specific hands-on engineering qualifications, you would gain very handy engineering management and project skills that apply equally well in both civvy and military fields. And meet some great people. If you went for an SSC then it would still give you time to have a second career in aviation outside of the military.
If you are interested in joining then the Mil Forum has a thread which has all the gen on joining
here. Just ignore all the pump about being a pilot.
Hope this helps.
I'll be interested to see what life/pay is like for civvy engineers.