IMO should be:
Stock Market
Social Security System
Interstate System
Disaster Relief Agency
Pentagon
Great Monument
Great Temple
Internet
Great University
SM is cheap for the first wonder and gives a decent bonus. should be bought at 4k infra.
SSS slightly more expensive, and increases income by a lot.
Interstate hugely cuts down the cost of infra (upkeep and initial purchase) and should be bought before the 5k infra jump.
DRA is useful because it opens the extra aid slot for buying tech faster.
Pentagon is good because just about any nation that old and that size will end up in a war and it will come in handy.
Great Monument means you can keep your gov. on something like democracy, get the +1 bonus for having the gov they want, +1 because democracy is awesome and gives +1 happiness anyways, and the environment bonus.
Great Temple is better than internet because it makes you immune to spy attacks on your religion (who does that anyways?) and takes away the small effort of changing it.
Internet is after those because those make it so you don't have to change gov/religion
Great University is next because by this point you should be over 3k tech, at which point this gives a +5.6 happiness bonus as opposed to the +5 given by the other 3. If you have 3k+ tech then this should be bought before the Temple/Monument/Internet