<A HREF="http://users.erols.com/chare/786.htm" target="_new">This Chart</A> should help you understand the specifics behind the model rating.
If you can provide us with your motherboard's brand, model and revision, we will be able to give you a much more accurate answer about compatibility and the ideal upgrade path, this information is usually found printed, etched or painted on the motherboard itself.
Although the 3200+ require PC-3200 memory (AKA DDR400) to run at its nominal 2.2GHz clockspeed (11 x 200MHz), Dual Channel memory is not a requirement but it will provide a marginal gain in performance.
You may be better off buying a <A HREF="http://www.newegg.com/app/ViewProductDesc.asp?description=19-103-401&depa=0" target="_new">Mobile Athlon XP 2500+</A> instead, it is meant to run at 1.866MHz using a 133MHz FSB but unlike its more expensive 3200+ sibling, it will let the user change the multiplier, allowing a lot more flexibility when it comes to setting non-standard frequencies.
Most XP-M will happily run at a frequency exceeding 2.3GHz on air cooling with a voltage bump depending on the quatily of the core. A higher FSB is desirable since it increase the available memory bandwidth but even if you are limited to a 133MHz FSB, an XP-M running at 2.4GHz (18 x 133MHz) will smoke a 2.2GHz 3200+.
Overclocking is the best way to get the most performance out of your hard earned money.
Watercooled Mobile Barton 2500+ @ 2.6GHz (200MHz x 13)
Abit NF7-S V2.0
2x 512MB of Samsung TCC4
Sapphire Radeon 9700 128MB @ 360/310
2x Maxtor 40GB 7200RPM RAID-1