How to arrange for a day trip to National Park de Hoge Veluwe and National Museum Paleis Het Loo?

I’m interested in a day trip from Amsterdam (close to Centraal Station) to both National Park de Hoge Veluwe, specifically for Krőller-Műller Museum, and National Museum Paleis Het Loo. Checked a few rental car companis like Avis/Hertz and the work hour are something like 8/9am to 5/6pm. It seems to be too rush to go back by 5/6pm if I’m visiting both places.

The question is more of three:
1. Is there a rental car company close later, say 8/9pm, that’s close to Centraal Station?
2. Is public transportation a viable option? I heard it’s about an hour’s train plus 45 min bus to just one of the place.
3. Is there any tour company organizing such tour that I can just sign up for it?

This is going to be part of my family’s vacation in Amsterdam next week.

Thanks in advance.

If you want to rent a car outside office hours (then without checking all of the companies) I know from experience that the branches of major companies (Hertz/Avis/Europcar/Sixt etc) are open longer hours from Schiphol airport. E.g. Avis at Schiphol is open 06:30 – 23:30 uur http://www.avis.nl/avisonline/nl/avis.nsf/fTopFrameSets/3B29025F9BB11DBFC12569EE00524C7E?OpenDocument&~Default&_S1_3B29025F9BB11DBFC12569EE00524C7E_N2_N3

Then it is just a matter of hopping on the train to Amsterdam Centraal which is simple and regular (about 15-20 mins max), so this could be an option for you.

I checked the public transport planner online http://www.9292ov.nl and there is of course a possibility to get to both by public transport (using times from today)

e.g. Amsterdam Centraal to Krőller-Műller Museum
11.22From A’dam CS by train to station Ede-Wageningen (train heading Nijmegen)
12.43From ede wageningen by bus108s (heading apeldoorn) to rotonde, otterlo
13.01From rotonde, otterlo by bus106 ( heading hoenderloo) to kroller muller museum
13.08Walk 4 mins from bus stop to museum

From kroller muller museum to National Museum Paleis Het Loo:
13.44From kroller muller museum walk 4 mins to bus stop
13:48From kroller muller museum stop by bus106 (heading otterlo) to rotonde, otterlo
14.00From rotonde, otterlo by bus 108s (heading apeldoorn) to apeldoorn
14.39From Apeldoorn bus station by bus104 (heading harderwijk) to gedenknaald, apeldoorn
14.43From gedenknaald, Apeldoorn walk 13 mins to museum paleis het loo apeldoorn

From National Museum Paleis Het Loo to Amsterdam CS
17.57From museum paleis het loo apeldoorn walk 3mins to bus stop tuinmanslaan, apeldoorn
18.00From tuinmanslaan stop to Apeldoorn train station by bus10 (heading Richtersweg)
18.23From Apeldoorn train station by train to Amsterdam CS takes 50 mins

Personally, looking at the amount of time & connections, I would go by car and so pick the rental car option

I am afraid I do not know any tour companies specifically for these two museums specifically – maybe someone else can help with this

Good luck