What cartridge should I try ?

I have a Nottingham Space Deck and Space Arm. Bat VK-P5 Phono With six-pac upgrade. Also VK-50SE Pre and VK-75SE amp
I had a vkp5 now a vkp10. with 50se and 75se. The Lyra cartridges match up great. I'm using the Lydian Beta, on the way to a Helikon soon.

what kind of music do you listen to? What speakers?
I listen to all types of music except country. Mostly Blues Older rock female vocals. I am using The Meadowlark Blue Herons for speakers.
My componants are different than what both of you are using, but I too am working towards a Lyra Helikon. I have a Benz Glider now and I'm very happy with it but...
The Helikon is far and away a better cartridge.
In our store we show the Nottingham Space Deck and Space Arm combo with a Dynavector 17D2 which is a great cartridge for the money ($750) and a common upgrade is to the XX-2 ($1650) which is a superb cartridge regardless of price. The Helikon is also an excellent choice but it is priced higher than either of the Dynavectors. The XX-2 is really superb and carries what I think is a very reasonable asking price given its extremely high level of performance
Lyra Helikon has the closest sonics to Koetsu Wood cartridge and might be your last one.
Shelter 901. A lot of discussion on this cartridge and its sibling 501 Mk II on Audio Asylum. I have a Benz M2 on my Michell Orbe SE/SME V. A friend first recommended to me to check out this cartridge. After hearing this cartridge at another friend's place, and did some research, I ordered one from a Japanese dealer for less than $1100 shipped express. It's sitting at home waiting for me to get a chance and mount it on my table.
Go do a search on AA vinyl forum and read all the raves about the Shelter 901 and 501 cartridges, and also this website with some reviews on the cartridge.

A lot of the websites point people to this Japanese website (www.eifo.com.jp) selling the 901 for over $1400. If you are interested, let me know, and I will dig out the contact information of the place I bought mine from. The guy's name is Akio Hashimoto. His contct information is also burried in couple of the discussion threads on the AA forum. Very nice guy to deal with.