I would suggest rearranging the order of your list.

Get the dry suit first, as it will be the piece you use the most and
it's the most critical to your safety. A Farmer John is nowhere near
adequate protection for North Shore paddling except in mid summer.
Spring is actually the most dangerous time of the year to paddle, IMO,
since the warm air lures people into under-dressing, but the water temps
are only in the 40's and can incapacitate and kill quickly. I find that
I wear a dry suit 7-8 months of the year and it's probably the single
best investment I've made in paddling gear. Get a waterproof/breathable
suit, as the cheaper coated nylon suits are sweat boxes. Definitely
insist on a relief zipper and I suggest that you also get latex or
Gore-Tex socks, as they significantly increase comfort. I haven't tried
a Palm dry suit (I've owned Kokatat and Stohlquist), but they appear to
be well made and I've heard good things about them. Ravenspring
(www.ravenspring.com) is another alternative that's very popular around
here.

Get the VHF next. It's your emergency lifeline to rescue services should
you find yourself (or someone else) in a life threatening situation that
you can't extricate yourself from. They come in handy for on water
communication with other paddlers and larger vessels. It's also great
for getting weather information, much better than the cheap weather
radios. The M1V is an excellent radio, but I like the M88 better (I own
both and have tried several others). There are frequently $50 rebates on
the M88, so you can get one for ~$200 if you catch a rebate and a sale.
Defender (www.defender.com) has the M1V on sale currently for ~$175.

A GPS is strictly optional. I have one, but never use it. A chart and a
deck mounted compass is simpler and more reliable. I would NEVER rely on
a GPS (or any other battery powered device) as my only means of
navigation. I would put this on the bottom of my gear list, after spare
clothing, dry bags, spare paddle, tow rig, bivy jacket or sack,
hydration pack, first aid kit, emergency hatch covers, etc.

You can work on your skills over the winter. The NSPN runs pool sessions
at several locations, where you can work on rolling and rescues. We also
run workshops on navigation, boat outfitting and other subjects. In the
spring, we have a trip leader training program where you can learn about
navigation, rescues and group management on the water in real
conditions, rather than just in a pool or on a pond. It's a great club.
http://www.nspn.org