G'day Phil,
Me personally, I would do both , but if I had to choose I'd talk to a router or someone with good knowledge of that route.
The reason. I find when the models don't align to the reality, I get kinda stuck as I don't have the advanced knowledge to look around and make a call. Aside from standing face into the wind and sticking my left arm out to ID where the centre of the low pressure is, the cupboard is a bit bare.
I am getting the hang of picking when the weather system is delayed or early, But when it is completely out of kilter I tend to get a bit lost. To me, a pro is more useful in that regard.
Lydia gave me some good advice as I was working up the boat for its first big offshore leg of the criticality of regular logging of your barometric readings. This was something I'd forgotten about and it really helps when trying to work out what is going on. Pressure doesn't lie!
If I could interpret what the clouds and weather were telling me I'd be happy to have just PW. So, the above could be more a reflection on my skill level than an analysis of the model capability.
When the models are out I typically find the next 6 hourly update will correct it. You prob know/have all this, but just for discussion I find internet acccess for updates is obviously the key to maximising the benefit. For me, this meant simply buying the cable for my satphone so I could download the grib. I went a bought a new hot spot sat phone for this reason, so I could plug in the stupidly short stubby cable for data download and sit comfortably to use the phone. Most times I've downloaded a 5 day forecast and trundled off it's kinda crap by day 3, so internet access is a good thing. A typical good res grib averages about 300kb, so it's only a couple of minutes on Thuraya sat phone, and Thuraya is cheap and fast for data with good plans.
I use PW standard subscription at $150 for three months, the pro version is about $350 for 3 months. there is a basic cheaper plan than these but unsure of details, I've just never bothered looking at it.
You don't need the Pro. The main difference is an increase in resolution from 8km to 1 km. The 1km is pretty impressive in its detail, but you kinda need to be Will Oxley to really benefit from it

. The sea temp Gribs and ocean currents in the Pro is really good also.
Sounds like a lot of fun Phil. Are you taking yours or someone elses?
Cheers,
SB