Need advice on what boat to buy

[Huno41]

I'm on December 23, 1939 and i want to make sure i can get the XXI as soon as it's available, however i wish to change to a type IX by 1941 or sooner because i find the VIIB range too short and i'd want to sink ships near america,
So should i:

1.Buy the IXC in mid 1941 and stick to it

2.Buy the IXB by the end of 1940 and get the IXC/40 by 1942

3.Or Buy the IXC in 1941 and then the IXC/40 in 42-43


I've got 10k renown already after 2 very successful patrols :D but i'm still worried i might not have enough to buy the XXI asap with options 2 and 3.
On a regular patrol i make 700-1000 renown but at late war i can see this number going down drastically i'm not sure. Also is the IXC/40 really worth buying if you already have the IXC?

[Fifi]

IXB & C are best for America coast hunting :yep:
... as it was in real life.
Don’t Recall any VIIB were sent over there, few VIIC made the trip, but many IX types hunted this part of Atlantic.
Type XXI never crossed Atlantic of what i know.
Make sure to be affected to Lorient base for America patrols.

:Kaleun_Salute:

[Jimbuna]

(2) Start in 2nd Flotilla and get the IXB as soon as it becomes available as well as automatic transfer to Lorient.