FWIW, Pale Ale malt & Maris Otter are very similar - both Ale Malts. MO is just a little more malty. I'd just use one or the other.
If you want malty, add some Munich to what you posted above. If you prefer more "caramelly", don't bother, just stick with the crystal.
Also, most of the crystals won't get you a red colour, more of a tan or amber brown. CaraAroma, Roasted Barley or Midnight wheat are more likely to get you there, and RedX will also. Shepherd's Delight might be able to do it as well - haven't brewed with that one yet.
So essentially, i'd suggest picking a single crystal to go with, then select a spec malt to get the red colour from there - whether it's lots of RedX or a bit of those others. Red colour can be a little tricky to hit - estimated colour (EBC) is the best indicator, but still quite hit-&-miss. This is especially so because of the interplay of brown contributing malts and the "red"contributing malts.
Hops wise, all of those hops work in all the permutations of combinations. You can not go wrong with Simcoe or Cascade, and apparently Mosaic. Chinook is a little more particular to individual tastes, but i think it's awesome in combination with any of those others and balances/compliments them particularly well. If pushed, i guess i'd probably go Chinook plus one of the others (Simcoe, i guess) in at FWH and 20 mins; then that "other" plus one more in as dry hops. So maybe Chinook+Simcoe in at FWH/90mins and at 20mins, then Simcoe & Mosaic as dry. Maybe a little of the 3rd one at 20mins also.
2c
Hope that helps!
