Reversing the order is not a good idea: read http://rdist.root.org/2009/10/29/stop-using-unsafe-keyed-has... for a readable introduction (summary: it works, but it maximally exposes you to any possible problems.) Just use HMAC, especially if you want to use SHA1 - which is not broken, but no longer above suspicion.

I agree that this scheme is probably fine as long as you're the only one using it and nobody is specifically targeting you; but if you're going to go to use a password manager (which would be an improvement in general - as you point out, "123456 is secure enough, no?" is prevalent), why not use a good password manager?