I currently have 18 x 9 +30 on the front with 18 x 10.5 +38 on the rear. Absolutely regretted it. Ended up putting 15 mm spacers on front and 25 mm spacers on the rear. Not to mention the rears were like a mm from hitting the coilovers. Definitely would go more aggressive then what you were originally planning. Keep in mind my guards are rolled and cars fair low so you might possibly need to roll guards depending how aggressive you go and how low the car is. Im not an expert but the
18 x 8.5 +25
18x9.5 +30
Sounds like it would sit much better.