I doubt there's any Mystery Dungeon starter kits tbh, however, by using the normal poke essentials, I'm guessing you might be able to create one...
For example: The Pokémon character sprites are floating around all over the place. For the battle system, you would probably remove the second screen combining them all. Dungeon's would probably be easier to make using the random map feature. (maybe, I'm not exactly sure how it works completely) Changing the text box shouldn't be to much of a hassle, and when you add text, make sure it's bottom and is semi-transparent. (oh, and if you're not able to edit that you'll have to change the scripts for text back to normal probably, or something, lol) Anyway, for dungeon PokéMon you would probably make them events the went something like this.
Picture: [PokéMon attacking]
Move Route: Approach
Call Common Event: Battle (That's just for example, you may want to use the script feature instead)
Conditional Branch:
(health = 10% or w/e)
[blank] became terrified and is running away!
Self Switch A = On
or
[blank] was defeated!
Conditional Branch (recruiting possible switch = off)
end
or
[blank] would like to join your rescue team.
show choices: yes or no.
if yes: [blank] has joined your rescue team! Give [blank] a nickname?
show choices: yes or no
if yes: open text screen (full)
if no: end
Yea, that was just rough sketching of what it would probably look like. You could use Wichu's bank system without any problem, except by removing battling system, you would probably need to readd the gold system for basic RMXP and call the gold Poké... Hope that inspired you a little. XD
Note: Don't forget, in Mystery Dungeon games, evolution doesn't do that much enhancing of stats, nor stats are that high to begin with.