OH also this might already exist, so tell me if it does, but it would be nice to get non-staff weapons for spell casters from an RP perspective! For instance, I wanted to build a kind of lycan druid type character in a recent playthrough, with the idea being that he'd start human and take a lot of lycanthorn and plant tf items, and use a mix of healing magic and nature-y bow abilities, but equipping most bows meant my healing got kinda slashed. Just from a purely aesthetic/RP POV it would be nice to mix and match more, since we can do that so much w/ powers.
There are lots of non-staff weapons for casters, though none are a bow. As was said already, Whitewood is the closest, but it doesn't have any spellP nor is it a Catalyst. In terms of ranged, non-staff weapons with the catalyst tag, there's the Kitsune scrolls (Divine Blossom, Eternal Delusion, and Seasonal Rhapsody), though those don't provide spellP either so your best bet on a ranged catalyst weapon would be the Metal Wand, sold by Svern (the Caravan's man), as it has 10 spellpower and 5 spell penetration, and counts as a ranged magical attack. As it's a ranged weapon, bow powers (like Crowd Control), since those all just use a ranged weapon rather than specifically bows.
Additionally, since it's a one-handed weapon, you should use an off-hand catalyst too. In terms of offhand catalysts, the best for a pure caster (note, I think that ranged weapon powers with the Metal Wand use your spellcasting stuff for its damage, since it's a magic weapon) would be the Blank Scroll, which is also a Kitsune catalyst, since it's 10 for both spellPs and also 10 accuracy, but for early on you should probably use either the Lynx Totem or the Mage Wand. Both provide 5 spellpower and 10 spell penetration. Personally, all of my casters use the Metal Wand with the Mage Wand, since it's 15 total to both, but the Lynx Totem is a very close sidegrade to the Mage Wand, and may fit more for your character.