Hi there CMDR Shar,
Take a look at this Asp that one of my fellow CMDRs has suggested for exploration.
http://coriolis.io/outfit/asp/02A4D...i432i2f.AwRj-ZRLNsg=.Aw18WQ==?bn=Asp explorer
There is no cargo rack, but you could easily replace one of the AFMUs if needed.
You definitely need at least one AFMU, so you could fix some of the modules yourself.
IMO one AFMU is enough as you can replenish the 'ammo' with synthesis and materials gathered on the planets.
2 SRVs just in case one will get destroyed
By replacing the Power Plant and Power Distributors with 2A, using D Thrusters, we've manged to reduce the weight by quite a lot and in the same time extending the FSD jump range. This specific build has got 33.2LY which should be well enough in most of the cases.
IMO weapons and mining lasers are not really needed as it will only put additional mass to your ship and trust me, you'll hardly ever use them.
Tip from me: if you going to put D thrusters in your Asp, be careful when landing on planets with gravity 2.0 and above. It might be tricky.
Don't forget about the Advanced and Detailed scanners, slap some heat sinks on top of that and you are ready to go.
Safe journey CMDR
P.S. If I might ask, where are you planning to go? do you have any specific places you want to visit?