There is a strong possibility that Hex Poly will perform well for you. Hex Poly is a fairly firm feeling co-polyester string with fantastic spin potential. Like all of Golden Set's products, Hex Poly is a high-end premium quality product with an amazing price.
For tension ?, start off with whatever tension has worked well for you with other polyester tennis strings.
In the absence of shock related arm problems, it is highly recommended that you give polyester tennis string a try. Whatever non-polyester string you have been using, chances are it is significantly more elastic (softer) than a polyester. Keeping this in mind, starting off with a hybrid ? will provide a feel that is less of a departure from what you are familiar with. More specifically, installing Hex Poly in the mains together with a softer string like Golden Set Synthetic Gut in the crosses will accomplish this. Once you have familiarized yourself with the feel of Hex Poly in a hybrid setup, and assuming you are benefitting from the increased spin and ability to swing more aggressively, transitioning to a 'full' Hex Poly setup may be the next step.
Go with a tension ? that is about 10% less than your non-polyester preferred tension.
Before discounting Hex Poly as a viable option simply because it is a polyester, consider the following:
• Did you try the polyester by itself in a 'full' (non-hybrid ?) setup?
'Full' polyester setups are very stiff so it is not surprising that you were discouraged. A hybrid setup involving Hex Poly in the mains and a second softer string in the crosses will yield a string bed stiffness that is significantly softer and livelier than your previous experience.
• Did you use the same tension ? that you usually use for non-polyesters?
Tension can play a huge factor in how stiff your string bed feels. Because polyesters are considerably stiffer than non-polyesters (excepting aramids), using a lower tension for polyester is essential to achieving a desirable feel. Generally, a 10% reduction from your favoured non-polyester tension is an excellent first guess at what is going to work best for you. If the feel is still too stiff, then drop the tension another couple of pounds for your next restring.
Going with 17, the thinner gauge ?, will provide you with increased feel and spin. For you, durability is not a big enough concern to warrant using the thicker 16 gauge.
Going with 16 gauge ? will maximize durability while going with 17 gauge will provide an enhanced feel along with increased spin. It is a difficult decision for a lot of players because you inevitably are forced to sacrifice either durability or performance. Something of a compromise is obtainable by installing 16 gauge in the mains and 17 gauge in the crosses. Such a hybrid ? combination will yield durability on par with 16 gauge as well as improved performance.