bothers you, don't do it! Speed bumps in a CPU family have surprisingly limited, day-to-day performance effect on a system's response. For most workloads, Intel's CPUs seldom run at their max frequency and cache size for more than a few seconds, if that much. The satisfaction you will get from maxing out the CPU choice is peace of mind knowing that it can't get better, until the next gen CPU launches.
Get **at least** 1024MB mem.