If you do end up doing a Kickstarter, I'll be glad to back it if I'm in a situation to, regardless of which game you end up doing it for. Personally, I think the Rose sequel might be more successful, if only because you already have the first game to point to as a sign if you can successfully develop and publish a game. And that way you could bundle the first game in with it for the mid-range tiers (£30-50, I guess?) or otherwise have it as a backers' extra they can pick on top of whichever tier they choose.
I've seen quite a lot of people recommend having a Tumblr blog to promote whichever game you choose, and I second this. Just one word of warning though - I know more than a few devs who've burnt themselves out answering asks on Tumblr in addition to working on the game at the same time. I'd recommend trying hard to balance that (because it can be surprisingly difficult), and potentially prioritising asks on updates (probably just linking to the most recent KS one) and other asks that only need a short answer. The Wayhaven tumblr is probably good for this, because the dev's answers to LI reacts asks is usually one sentence per LI, even if it's a Choice game instead of a VN. It's a quick and easy way of appeasing fans, from what I've seen, although I imagine it can be pretty useful from a writer's perspective too.
Also, most KS devs do well with a monthly update - Quantum Suicide is a good example of one that's been considerably delayed (the sole dev got divorced and had to stop work temporarily for legal reasons during the divorce), but most of the backers are happy because we get regular updates, even if it's "not much happened". Same with Zodiac Axis and Lake of Voices, since I backed both of them and found the dev-backer communication pretty satisfying. It also might give you some ideas for how to layout the process of developing to your backers, if that helps?