Hmm if you wanted some extra bonuses with your left over 10 levels. . .
Picking up Harper Priest wouldn't be a bad I don't think (currently thinking...) it would give you that +4 natural armor bonus to save you a necklace slot too.
Hospitality is a great pick up too! (Atleast a 5 dip for 2 extra feats)
Storm Lord has always been one of my favorite classes (although I never made one... but ive seen people play them and they look cool!) And speaking of storm-lord i'm preety damn sure if you storm avatar the bonus electric dmg applies to the shield bash dmg no? Since it's a character buff and not a general weapon buff.
Personally I think your best bet is going with Rain's suggestion, so long as Hospitaler rules can fit within your RP and/or Dogma of the deity you are a Favored Soul to. Usually the Hospitaler bonus feats at 5 and 9 would be taken in Epics, one of the feats is essentially 'lost' since you need to take Practiced Spell Caster. However, the other two should make it far easier to get at least the 4 most important shield feats (bash, knockdown, charge and slam).
Since you are wanting to go shield slam I assume you are maxing out STR while leaving CHA at ~16-17 (20 w/ item). Since not going the FvS EDM/Divine Shield route this opens up 3 feats many FvS builds take (PA, DM, DS). So with your 7 pre-epic feats you can grab Shield Bash, KD, Charge, Slam. I forget if Hospitaler gets Tower Shields, but if not you may want to grab that feat as well. As to your other feats, Extend Spell and Practiced Caster are paramount and IKD isn't a bad idea.
Now, the other option (should Hospitaler not fit) is to simply go full FvS 30). I mean, you do get 3 epic bonus feats this route! As stated above you don't really *need* many feats for a favored soul... Pretty much extend spell and your good, the rest is judgement call. Most people would be going PA, DM, DS, maybe IPA, LoH or Blindfight? For your build, as a pure favored soul you could take Luck of Hero's, Shield Bash, KD, Shield Charge, Shield Slam, Extend Spell and then perhaps Northlander Hewing (great for a STR Focused Shield Slam build). There is your 7 pre-epic feats (and you get one more if human). I suppose you could go FvS26/Hospitaler 4, but the one bonus feat is lost on Practiced Caster so really you are giving up an epic feat for weak Lay on Hands and Cure Disease.
I would never play a build that only gets CL24 without having HiPS. That just seems like it'd be a recipe for frustration.
Another build would be 22 FvS/ 4 HP /4 DC -- Would still give you 2 extra feats that you would've gotten from Hosp but also nets you 2 extra saves. Hosp, imo, would only be worth it if the build is looking for 10 lvls of Hosp.
