what 's the best tonearm for turntable

I have a Pioneer series 20 turntalbe with a Lustre GST 801 and want to change for an straihght tonearm but i don't now which size might the best, thanks for your help
Check Vinyl Engine for arm length of Lustre and see which straight arm is a similar length. The 801 is a good arm, is there any particular reason you want to change?
I hope someone can help find another straight arm with a 225mm mounting distance (like the Lustre GST-801. The only ones I know of are the Audio Technica AT-1100 and AT-1120, and possibly the Sonus, but they are all for lightweight carts.

The Hadcock GH242 is 1mm too long (226mm mounting distance according to my data) and the Dynavector arms (not straight, but weird enough to be included) are also 1mm too long, and the Magnepan Unitrac is 1mm too short.

Disclosure #1: I actually put an 1100 up for sale as part of a turntable set around the time of this thread without knowing this thread was there. Disclosure #2: I'd probably rather have the GST-801.
I have had both the 801 and the 1100, but it was 25+ years ago. If I wanted to use MM I would probably go with the 1100, MC the 801 but both are good arms.
Dear Jhreyes: I don't know why you want to change for straight tonearm design that can give you no advantages and where you can loose all the GST-801 advantages it has.

IMHO your Lustre is one of the best tonearm designs out there and you maybe can't do better with almost any other tonearm it does not matters what you want to pay because even tonearms in the 5K+ price can't outperform it.

Btw, who give you that tonearm advise that made you want to change the GST-801?, with all respect IMHO is totally wrong with out single know how on that advise.

Regards and enjoy the music,