IIRC the original Clunk wings were a bit on the lightly-built side, so you'd either need to go easy on the load or write something into the backstory about newm stronger wings being fitted for the air-to-ground role. Probably better to stick to the short Mk.4 wings as well. Rebuilt Clunks doing CAS/COIN in a Canada-in-Vietnam scenario is an intriguing thought.
A SEAD Clunk might use Shrike instead of MARTEL, especially if it's not British (or if it's British-in-Vietnam and we buy the US missile in a hurry).
MARTEL weighed about 1200lb.
Shrike weighed about 390lb.
A dedicated SEAD platform would need all the other gear as well: an ALQ-series ECM jamming pod and an internal emitter location system, probably replacing the radar and the gunpack. You could have large tip pods with fuel in the middle and ESM/ECM aerials in their nose and tail sections. There's also plenty of scope for aerials in the rear fuselage, given that the jetpipes aren't in the way.
The Javelin was a tank and could probably take a ton of ordnance without difficulty, indeed, there were several real-world schemes for strike-versions of it. Bear in mind that fitting a centreline pylon isn't as simple as it looks: there was a big belly hatch and an empty space right in the middle of the fuselage for maintenance access to the engines (yes, really...
). The wings were complicated and counter-intuitive too. It'd be a good idea for anyone thinking about Javelin mods to gaze long upon a good cutaway drawing of the thing: it really is headscratchingly odd in places.
