ais/garmin/sea clear

[sabray]

Question 1)
I am about to hook up a milltech ais to a garmin 4208 using nmea 0183. Reported prior somewhere were difficulties with garmin 4000 and 5000 series chartplotter and milltech. milltech suggests usting a 420 ohm resistor with these Garmin products. has any one hooked one up recently.
The garmin input has adjustment for baud rates. But the problem looked more like a signal strength issues.
Question 2)
Having played with sea clear and noaa raster charts the program worked well. Does any one have experience integrating and using seac clear milltech and garmin 4000 and 5000 series chartplotters.THe 2 options I see using a com port to usb bus or using milltechs splitter that has 2 com ports, and an Nema 0183 branch. Also would need a converter com to usb.
Your experience appreciated.