Several things here:
1. You have a Touring trim Mazda5, so that means 17 inch wheels with 205/50/17 tires. You can always go down to 16 inch wheels with taller 205/60/16 or 215/55/16 tires. This will add extra cushion and mitigate road imperfections. But buying new wheels and tires can easily cost more than replacing shocks and struts.
2. What "soft" shocks/struts are you talking about? Details matter. Where did you read about these? The only options I've seen are OEM-equivalents or higher-performance/adjustable shocks/struts.
3. Your Mazda5 is 10 years old. I have no idea how many miles are on it. It's not the worst thing ever to simply replace your shocks and struts. It doesn't have to be terribly expensive, but of course if you're paying a shop to supply the parts and do the work, it'll cost a lot more. I recommend you source your own shocks, struts, and strut mounts. What is your budget?
4. I can personally recommend Bilstein B4 replacement shocks/struts. Also KYB G2 or Gas-A-Just are very decent aftermarket shocks/struts. If you had the budget, you could get Koni Yellow adjustable shocks/struts and place them on the most comfortable setting, but these will really be a much more expensive option.
