Are the options qualified (ISO) or non-qualified (NSO)? There are tax consequences to consider. I'd suspect non-qualified since they're offering an RSU, but you should confirm.
RSU will probably be taxed when they vest, and the stock option (NSO) I 'think' (double check this) won't be taxed unless you exercise, and qualified options (ISO) won't be taxed at all if you meet the holding requirements. ISOs might subject you to AMT taxes though if they are worth a lot. If you don't meet the holding requirements the IRS will treat the option as an NSO and tax you accordingly and it will be painful.
You'll have to cough up money to exercise the options but I'd expect the company to have a way to exercise without any out of pocket expense, they basically exercise and sell some of the options to cover the exercise cost, so you don't have to pay anything but end up with less options. If you can afford it you can pay the exercise price and keep all of the options.
Also, you'll want to get familiar with the 83b tax election if you expect the company stock price to increase. It lets you pay tax on the present value when the stock is granted rather than when the stock vests. Obviously the risk is if the stock value goes down, you paid extra tax.
DO NOT IGNORE 83b! It could save you tons in taxes.
If you get options, also ask if you they will allow you to early exercise them before they vest. You can then early exercise the option, and at this time file an 83b election. The 83b applies only to stocks, so it applies to the RSUs, but the option converts to stock when you exercise so you'd need to file 83b when you exercise the options. It's a bit convoluted so get a tax professional to advise you.
If you early exercise the options you'll definitely want the 83b or you'll be totally screwed on taxes. I can't emphasize this enough, to make a good decision here you need to understand how ISOs, NSOs and RSUs are taxed and how you think the company stock valuation will change as they vest.
If they allow early exercise and the strike price is equal to the share price NSO might make more sense than an ISO since the profit (and tax) at exercise will be zero. This applies more to non-public companies which are valued less frequently than a publicly traded company and you can exercise early before the valuation deviates from the strike.