For 1/48 scale, the only option I know of regarding weapons kits are the Hasagawa "aircraft weapons" kits. These are boxed "A" through "D" and include some weapons used today. They are also great for Vietname era planes, as they have some older missiles and bombs as well.
For an F-15E, the following kits would be good for you:
Hasagawa Aircraft Weapons "A": contains lots of Mk82s, 2 Mk84s, and 6 Mk20s.
Hasagawa Aircraft Weapons "B": contains 2 GBU-10s and 4 GBU-12s
Hasagawa Aircraft Weapons "C": contains 4 AIM-9Ls that can be fashioned to look like AIM-9Ms. It also contains 6 AGM-65s.
Hasagawa Aircraft Weapons "D": contains 6 GBU-12s, 2 GBU-16s, 2 GBU-24s, 2 GBU-10s, and 2 GBU-31s (JDAM)
The above kits contain a lot more weapons, but the ones I lised above are those that the F-15E can carry.
I haven't been able to find after-market kits that contain ordance that is carried by the F-15E in recent strike missions. This would include JASSM, JSOW, WCMD clusters, any CBUs, AGM-130, BLU-118 (thermobaric), GBU-15, or GBU-28.
Hope that helps,
- Snacko